Tetramorium anodontion, Bolton, B., 1979

Bolton, B., 1979, The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Malagasy region and in the New World., Bulletin of the British Museum (Natural History) Entomology 38, pp. 129-181 : 156

Tetramorium anodontion sp. n.

(Figs 22, 23)

Holotype worker. TL 2.6, HL 0.68, HW 0.60, CI 88, SL 0.48, SI 80, PW 042, AL 0.74.

Mandibles appearing dull and finely shagreened. (This appears to be an artifact caused by the presence of a waxy layer on the surface of the mandibular blades. In thoroughly cleaned paratypes the mandibles are shining with scattered pits.) Anterior clypeal margin entire, without notch or impression medially. Frontal carinae strong, convex along their length and surmounted by a narrow rim or flange, tending to peter out occipitally and become indistinguishable from the remaining sculpture. Eyes of moderate size, their maximum diameter 0.15, about 0.25 x HW. With the head in full-face view the sides immediately behind the eyes lacking a projecting stout hair. Outline of alitrunk as in Fig. 23, the metanotal groove very weakly marked. Propodeum absolutely unarmed, without trace of spines or teeth. Metapleural lobes broad and bluntly triangular. Node of petiole in dorsal view broader than long. Dorsum of head strongly sculptured, with numerous fine longitudinal rugulae and the interspaces packed with conspicuous reticulate-puncturation which also covers the scrobal areas. Dorsal alitrunk, petiole and postpetiole finely reticulate-rugulose, all interspaces covered by dense, distinctive reticulate-puncturation. First gastral tergite with faint shagreening basally but otherwise unsculptured. Short, stout, blunt hairs present on all dorsal surfaces of head and body. Colour medium brown, dull.

Paratype workers. TL 2.5 - 3.1, HL 0.62 - 0.76, HW 0.57 - 0.68, CI 88 - 93, SL 0.45 - 0.54, SI 76 - 80, PW 0.40 - 0.47, AL 0.72 - 0.86 (18 measured). Maximum diameter of eye 0.14 - 0.17, about 0.24 - 0.25 x HW. As holotype but in a number of workers the waxy layer on the body has been lost so that in some the gaster appears dull, in others polished. In the clean specimens the shagreening of the first gastral tergite is more conspicuous.

Holotype worker, Madagascar: ' Bekonazy to 5 km S. forest W baobabs (n. of Morondava) 24 Mar. 1969, dry forest. M 214, rot. pod of legum tree, shade' (W. L. Brown) (MCZ, Cambridge). Paratypes. 28 workers with same data as holotype (MCZ, Cambridge; BMNH).

T. anodontion is unique in the Malagasy fauna of Tetramorium as it is the only species yet discovered in which the propodeum is completely unarmed.